The present invention relates to a slide fastener with a bottom stop of the type in which discrete interlocking fastener elements are cast onto the stringer tapes, via the beads attached thereto, by a pressure casting or die casting process. The bottom stop, as is well known, serves to inseparably secure the two halves of the slide fastener as well as to simultaneously limit the movements of the slider.
It has been long taken for granted in this art that a semi-finished-product slide fastener without a slider is much preferred to a finished-product slide fastener with a slider already incorporated therein, when being sewn to an article such as a garment fabric; since, in the case of a finished-product slide fastener, the already incorporated slider is liable to block the sewing needle or needles, of lowering of manufacturing efficiency. However, until now this has been a manufacturer's vain wish since in the bottom stop of metal or plastic has usually not been attached to the stringers until the latter has a slider mounted thereon.
One attempt to treat the problem is taught in U.S. Pat. No. 3,104,438 of Sept. 24, 1963 disclosed a slide fastener carrying a bottom stop which consists of three parts, one being attached to one stringer and the other two the other stringer, which are adapted to be assembled by being passed through the slider and permanently joined thereafter, to thereby a bottom stop.
However, it is to be noted that this prior art bottom stop, for at least one part thereof, must have a structural formation of such greater lateral dimension across the longitudinal axis of the slide fastener as to present, when the bottom stop parts are interengaged by the slider, a positive stop adapted for direct abutting opposition to movement of the slider in the direction of fastener element opening. This means that at least one part is wider than the the neck portion of the slider and the corresponding flange and consequently must be forcibly and compressedly thrust therebetween when inserted together with the other parts into the slider for assemblage therewith for presentation of the permanent bottom stop. This forcible thrust is liable to cause damage on and the bottom end part itself, the flange and/or the neck portion of the slider through which it is thrust, which naturally impairs the function as a bottom stop. In addition to this, the parts 6 and 7 of the prior art bottom stop are not designed to be stably held against displacement from each other perpendicularly to the plane of the slide fastener at their lower portion although they are so designed at their upper portion, so that the parts are liable to get out of proper coupling engagement with each other.
With the foregoing disadvantages of the prior art in view, it is a primary object of this invention to provide a slide fastener having a bottom stop comprising three parts which have a specific construction which enables them to smoothly enter the slider, without being forcibly compressed, for assemblage therebetween, and which, once they enter the slider, are assembled to provide a bottom stop, and provide a reliable function as such for a prolonged period of time.
It is a second object of this invention to provide a slide fastener having a bottom stop comprising three parts which has the specific construction to prevent them from getting displaced from each other particularly perpendicularly to the plane of the slide fastener even when subjected to severe stresses tending to move these respective parts normal to the same plane.
It is a third object of this invention to provide a slide fastener having a bottom stop comprising three parts which are brought onto the stringer tapes simultaneously when and in the same working operation as are the fastener elements, hence dispensing with any subsequent additional attaching operation, increasing the manufacturing efficiency.
It is a fourth object of this invention to provide a slide fastener having a bottom stop of the specific construction permitting passage of a slider therethrough subsequent to the mounting of the bottom stop upon stringers, consequently permitting sewing operation of the stringers without a slider or what we call "a semi-finished-product slide fastener without a slider" onto an article, thus leading to great enhancement of manufacturing efficiency.
The above objects are attained according to the present invention in a slide fastener comprising: (a) a pair of flexible stringer tapes carrying resilient marginal beads on and along the respective inner longitudinal edges thereof; (b) two rows of discrete interlocking fastener elements mounted on and along said marginal beads; (c) a slider slidably mounted on said rows of interlocking fastener elements and adapted to reciprocally slide along said interlocking fastener element rows to engage or disengage them for opening or closing of said slide fastener, said slider having a flared front end and a tapered rear end and including a neck portion formed centrally on said flared front end and a pair of opposed side flanges formed on its sides to define therebetween a Y-shaped channel for reciprocal slidable passage of said interlocking fastener element rows therethrough; and (d) a bottom end stop attached to said marginal beads at one end of said rows of interlocking fastener elements, said bottom stop including a first member mounted on one bead and adapted to engage at its upper part with the lower most interlocking fastener elements carried on the other bead, a second member mounted on said one bead a given distance below said first member and a third member mounted on said other bead a given distance below said lowermost element and disposed in opposed relation to the lower part of said first member and said second member, said third member being adapted to engage at its upper part with said first member so as to slide transversely of and along the plane of said slide fastener and to engage at its lower part with said second member so as to pivot along the plane of said slide fastener, said third member being in the shape of a polygon comprising an interior side lying inwardly of said other bead, side lying outwardly of said other bead, an upper interior corner contiguous to said interior side and an upper exterior corner contiguous to said exterior side, said third member being provided adjacent the upper interior corner with an abutment for abutting engagment with said neck portion of said slider, said upper interior corner being above said upper exterior corner thus to leave said resilient bead intact beside the former, the dimension of said third member to be measured perpendicularly to the side of said neck portion, as disposed when passing between said side of said neck portion and said corresponding flange, is slightly smaller than the distance between said side of said neck portion and said corresponding flange.
The above and other objects, features and advantages of this invention and the manner of attaining them will become more readily apparent, and the invention itself will best be understood, from the following description of preferred embodiments taken in connection with the acompanying drawings .